If you're working on a complex workflow and want to see how it behaves without a certain action, click on the action's number on the left-hand side of the title bar. A pop-up menu will allow you to select *Disable*; the action will now be dimmed out, and the workflow will ignore it. This menu also appears as a ctrl (right) click on the title bar, and allows you to add a custom name, reorder or delete the action from the workflow.